Study type: Medical/biological study (experimental study)

Thermoregulatory responses of rats exposed to 9.3-GHz radiofrequency radiation. med./bio.

Published in: Radiat Environ Biophys 1989; 28 (1): 67-77

Aim of study (acc. to author)

To compare the acute effects of continuous wave and pulsed 9.3 GHz radiofrequency irradiation upon the thermoregulatory responses and related physiological processes in anesthetized rats.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 9.3 GHz
Modulation type: pulsed
Exposure duration: intermittent*
Exposure 2: 9.3 GHz
Modulation type: CW
Exposure duration: intermittent*

General information

*The exposure was discontinued when the colonic temperature increased to 39.5?C and it was initiated again when the temperature returned to 38.5?C. This procedure was continued for 8 cycles.

Exposure 1

Main characteristics
Frequency 9.3 GHz
Charakteristic
Polarization
Exposure duration intermittent*
Additional info Animals wre exposed in H-orientation (long axis parallel to magnetic field)
Modulation
Modulation type pulsed
Pulse width 2 µs
Repetition frequency 500 Hz
Exposure setup
Exposure source
Distance between exposed object and exposure source 1.5 m
Chamber Eccosorb RF-shielded anechoic chamber maintained at 24?C and 50% humidity
Setup Rats placed on a holder.
Additional info The holder consisted of seven 0.5 cm (O.D) Plexiglas rods mounted in a semicircular pattern on 4 cm x 6 cm Plexiglas plates (0.5 cm thick).
Parameters
Measurand Value Type Method Mass Remarks
power density 600 W/m² mean measured - 18.6 W/kg corresponding average whole body SAR
power density 300 W/m² mean measured - 9.3 W/kg corresponding average whole body SAR

Exposure 2

Main characteristics
Frequency 9.3 GHz
Charakteristic
Polarization
Exposure duration intermittent*
Additional info Animals were exposed in H.orienation (long axis parallel to magnetic field)
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 1.5 m
Parameters
Measurand Value Type Method Mass Remarks
power density 300 W/m² mean measured - 9.3 W/kg corresponding average whole body SAR
power density 600 W/m² mean measured - 18.6 W/kg corresponding average whole body SAR

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

There were no significant differences between the effects of continuous wave and pulsed wave exposure. At both power densities, the subcutaneous and tympanic temperature increases significantly exceeded the colonic temperature increase. At both irradiation levels, heart rate increased significantly and returned to baseline when exposure was discontinued. Blood pressure and respiratory rate did not significantly change during exposure.
The levels of subcutaneous heating and heart rate change were greater, and the times required to achieve and to recover from a 1°C colonic temperature increase were longer than in previous investigations conducted at 2.8 GHz (e.g. publication 9288). Data of these studies suggest that the carrier frequency used during irradiation markedly affects the pattern of heat distribution and the physiological responses of radiofrequency-irradiated rats.

Study character:

Study funded by

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